The screening of a biological sample for contaminants plays a vital role especially in the area of clinical medicine . The potential contaminants include infectious bacteria, disease causing viruses and parasites that can seriously compromise the health of a mammal, and even lead to death. It is important to screen for such pathogens in order to prevent the transmission of such diseases as caused by these contaminants. For example, it is critical to evaluate blood that was obtained from a donor prior to a transfusion into a recipient. This evaluation consists of screening the blood for the presence of any pathogen. Typically, this evaluation is performed in a laboratory well equipped for such a task. However, in certain milieus, the presence of a sophisticated laboratory is not a realistic expectation.
The screening of a biological sample is not limited to examining whether or not the sample is contaminated. Screening a biological sample is often done diagnostically, looking for the presence, or absence, of certain indicating biomolecules. An example of this scenario is when the blood is analyzed for the presence of certain lactate dehydrogenase isozymes which are particular to the heart. If these isozymes are present in the blood, this is indicative of a myocardial infarction. Also, testing is conducted looking for the presence, or absence, of genetic markers whether as expressed proteins (for example, MHC antigens) or in the genome. Again, these types of tests are usually performed in technically sophisticated laboratories.
A need exists for the ability to conduct screening of biological samples in environments that are not generally associated with technically sophisticated laboratories.